# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import gettext
import logging
from itertools import chain, cycle, islice

from gi.repository import Gdk, GLib, Gtk

from tryton.common import MODELACCESS
from tryton.common.datetime_ import Date, Time

_ = gettext.gettext
logger = logging.getLogger(__name__)


def focusable_cells(column, editable=True):
    for cell in column.get_cells():
        if (not editable
                or (isinstance(cell, (
                            Gtk.CellRendererText,
                            Gtk.CellRendererCombo))
                    and cell.get_property('editable'))
                or (isinstance(cell, Gtk.CellRendererToggle)
                    and cell.get_property('activatable'))):
            yield cell


class TreeView(Gtk.TreeView):
    display_counter = 0

    def __init__(self, view):
        super(TreeView, self).__init__()
        self.view = view

    def next_column(
            self, path, column=None, cell=None, editable=True, _sign=1):
        if cell:
            cells = list(focusable_cells(column, editable))
            if len(cells) > 1:
                idx = cells.index(cell) + _sign
                if 0 <= idx < len(cells):
                    return (column, cells[idx])
        columns = self.get_columns()
        if column is None:
            column = columns[-1 if _sign > 0 else 0]
        model = self.get_model()
        record = model.get_value(model.get_iter(path), 0)
        if _sign < 0:
            columns.reverse()
        current_idx = columns.index(column) + 1
        for column in islice(cycle(columns), current_idx,
                len(columns) + current_idx):
            if not column.name:
                continue
            widget = self.view.get_column_widget(column)
            try:
                record.load(column.name, process_exception=False)
            except Exception:
                logger.error(
                    f"Error loading '{column.name}' for {record}",
                    exc_info=True)
                return (None, None)
            field = record.group.fields[column.name]
            field.state_set(record, states=('readonly', 'invisible'))
            invisible = field.get_state_attrs(record).get('invisible', False)
            if not column.get_visible():
                invisible = True
            if editable:
                readonly = widget.attrs.get('readonly',
                    field.get_state_attrs(record).get('readonly', False))
            else:
                readonly = False
            if not (invisible or readonly):
                cells = list(focusable_cells(column, editable))
                if cells:
                    cell = cells[0 if _sign > 0 else -1]
                else:
                    continue
                return (column, cell)
        return (None, None)

    def prev_column(self, path, column=None, cell=None, editable=True):
        return self.next_column(
            path, column=column, cell=cell, editable=editable, _sign=-1)


class EditableTreeView(TreeView):
    leaving_record_events = (
        Gdk.KEY_Up, Gdk.KEY_Down, Gdk.KEY_Return)
    leaving_events = leaving_record_events + (
        Gdk.KEY_Tab, Gdk.KEY_ISO_Left_Tab, Gdk.KEY_KP_Enter)

    def on_quit_cell(
            self, current_record, column, renderer, value, callback=None):
        current_record.load(column.name, process_exception=False)
        field = current_record.group.fields[column.name]
        widget = self.view.get_column_widget(column)

        # The value has not changed and is valid ... do nothing.
        if value == widget.get_textual_value(current_record) \
                and field.validate(current_record):
            if callback:
                callback()
            return
        if widget.renderer != renderer:
            for widget in chain(widget.prefixes, widget.suffixes):
                if widget.renderer == renderer:
                    break
            else:
                raise ValueError("Unknown renderer")
        widget.value_from_text(current_record, value, callback=callback)

    def on_open_remote(self, current_record, column, create, value,
            entry=None, callback=None):
        widget = self.view.get_column_widget(column)
        if value != widget.get_textual_value(current_record) or not value:
            changed = True
        else:
            changed = False
        try:
            widget.open_remote(current_record, create, changed, value,
                callback=callback)
        except NotImplementedError:
            pass

    def on_create_line(self):
        access = MODELACCESS[self.view.screen.model_name]
        model = self.get_model()
        limit = (self.view.screen.size_limit is not None
            and (len(model) >= self.view.screen.size_limit >= 0))
        if not self.view.creatable or not access['create'] or limit:
            return
        if self.view.screen.new_position == 0:
            method = model.prepend
        else:
            method = model.append
        new_record = model.group.new()
        res = method(new_record)
        sequence = self.view.attributes.get('sequence')
        if sequence:
            model.group.set_sequence(
                field=sequence, position=self.view.screen.new_position)
        return res

    def set_cursor(
            self, path, focus_column=None, cell=None, start_editing=False):
        self.grab_focus()
        if focus_column:
            widget = self.view.get_column_widget(focus_column)
            if isinstance(widget.renderer, Gtk.CellRendererToggle):
                start_editing = False
        self.scroll_to_cell(path, focus_column, use_align=False)
        if cell:
            self.set_cursor_on_cell(path, focus_column, cell, start_editing)
        else:
            super(EditableTreeView, self).set_cursor(
                path, focus_column, start_editing)

    def set_value(self):
        path, column = self.get_cursor()
        if not path or not column or not column.name:
            return True
        for renderer in column.get_cells():
            if renderer.props.editing:
                widget = self.view.get_column_widget(column)
                editable = widget.get_editable(renderer)
                self.on_editing_done(editable, renderer)
        return True

    def on_keypressed(self, entry, event, renderer):
        path = self.get_cursor()[0]
        column = self.get_column_from_renderer(renderer)
        model = self.get_model()
        record = model.get_value(model.get_iter(path), 0)
        self.display_counter += 1  # Force a display

        leaving = False
        if event.keyval == Gdk.KEY_Right:
            if isinstance(entry, Gtk.Entry):
                if entry.get_position() >= \
                        len(entry.get_text()) \
                        and not entry.get_selection_bounds():
                    leaving = True
            else:
                leaving = True
        elif event.keyval == Gdk.KEY_Left:
            if isinstance(entry, Gtk.Entry):
                if entry.get_position() <= 0 \
                        and not entry.get_selection_bounds():
                    leaving = True
            else:
                leaving = True

        if event.keyval in self.leaving_events or leaving:
            if isinstance(entry, (Date, Time)):
                entry.activate()
                txt = entry.props.value
            elif isinstance(entry, Gtk.Entry):
                txt = entry.get_text()
            elif isinstance(entry, Gtk.ComboBox):
                active = entry.get_active()
                if active < 0:
                    txt = None
                else:
                    model = entry.get_model()
                    index = entry.get_property('entry-text-column')
                    txt = model[active][index]
            else:
                return True
            keyval = event.keyval
            entry.handler_block(entry.editing_done_id)

            def callback():
                entry.handler_unblock(entry.editing_done_id)
                if (keyval in [Gdk.KEY_Tab, Gdk.KEY_KP_Enter]
                        or (keyval == Gdk.KEY_Right and leaving)):
                    GLib.idle_add(self.set_cursor, path,
                        *self.next_column(path, column, renderer), True)
                elif (keyval == Gdk.KEY_ISO_Left_Tab
                        or (keyval == Gdk.KEY_Left and leaving)):
                    GLib.idle_add(self.set_cursor, path,
                        *self.prev_column(path, column, renderer), True)
                elif keyval in self.leaving_record_events:
                    fields = list(self.view.widgets.keys())
                    if not record.validate(fields):
                        invalid_fields = record.invalid_fields
                        col = None
                        for col in self.get_columns():
                            if col.name in invalid_fields:
                                break
                        GLib.idle_add(self.set_cursor, path, col, None, True)
                        return
                    if ((
                                self.view.screen.pre_validate
                                and not record.pre_validate())
                            or (not self.view.screen.parent
                                and not record.save())):
                        GLib.idle_add(
                            self.set_cursor, path, column, None, True)
                        return
                    entry.handler_block(entry.editing_done_id)
                    if keyval == Gdk.KEY_Up:
                        self._key_up(path, model, column)
                    elif keyval == Gdk.KEY_Down:
                        self._key_down(path, model, column)
                    elif keyval == Gdk.KEY_Return:
                        if self.view.screen.new_position == 0:
                            new_path = self._key_up(path, model)
                        else:
                            new_path = self._key_down(path, model)
                        GLib.idle_add(self.set_cursor, new_path,
                            *self.next_column(new_path), True)
                    entry.handler_unblock(entry.editing_done_id)
                else:
                    GLib.idle_add(self.set_cursor, path, column, None, True)
            self.on_quit_cell(record, column, renderer, txt, callback=callback)
            return True
        elif event.keyval in [Gdk.KEY_F3, Gdk.KEY_F2]:
            if isinstance(entry, Gtk.Entry):
                value = entry.get_text()
            elif isinstance(entry, Gtk.ComboBox):
                active = entry.get_active()
                if active < 0:
                    value = None
                else:
                    model = entry.get_model()
                    index = entry.get_property('entry-text-column')
                    value = model[active][index]
            else:
                return True
            entry.handler_block(entry.editing_done_id)

            def callback():
                widget = self.view.get_column_widget(column)
                value = widget.get_textual_value(record)
                if isinstance(entry, Gtk.Entry):
                    entry.set_text(value)
                else:
                    entry.set_active_text(value)
                entry.handler_unblock(entry.editing_done_id)
            self.on_open_remote(record, column,
                create=(event.keyval == Gdk.KEY_F3), value=value,
                callback=callback)
        else:
            field = record.group.fields[column.name]
            if isinstance(entry, Gtk.Entry):
                entry.set_max_length(int(field.attrs.get('size', 0)))
            record.modified_fields.setdefault(column.name)
            return False

        return True

    def _key_down(self, path, model, column=None):
        if path[0] == len(model) - 1 and self.view.screen.new_position == -1:
            self.on_create_line()
        new_path = Gtk.TreePath((path[0] + 1) % len(model))
        if not column:
            column, cell = self.next_column(new_path)
        self.set_cursor(new_path, column, start_editing=True)
        self.scroll_to_cell(new_path)
        return new_path

    def _key_up(self, path, model, column=None):
        if path[0] == 0 and self.view.screen.new_position == 0:
            self.on_create_line()
            new_path = Gtk.TreePath(0)
        else:
            new_path = Gtk.TreePath((path[0] - 1) % len(model))
        if not column:
            column, cell = self.next_column(new_path)
        self.set_cursor(new_path, column, start_editing=True)
        self.scroll_to_cell(new_path)
        return new_path

    def on_editing_done(self, entry, renderer):
        path = self.get_cursor()[0]
        if not path:
            return True
        column = self.get_column_from_renderer(renderer)
        model = self.get_model()
        record = model.get_value(model.get_iter(path), 0)
        if isinstance(entry, (Date, Time)):
            entry.activate()
            text = entry.props.value
        elif isinstance(entry, Gtk.ComboBox):
            model = entry.get_model()
            iter_ = entry.get_active_iter()
            if iter_:
                text = model.get_value(iter_, entry.props.entry_text_column)
            else:
                text = ''
        else:
            text = entry.get_text()
        self.on_quit_cell(record, column, renderer, text)

    def get_column_from_renderer(self, renderer):
        for column in self.get_columns():
            for cell in column.get_cells():
                if cell == renderer:
                    return column
